Abstract: Employee #1 had erected a temporary wooden guardrail around the top of the stairway leading into a metro rail station where the employer had laid approximately 8 ft square by 1 in. thick iron deck mats. The mats were to be used for placing crane loads of material that then could be slid down on either side of the new stairway. When the job was completed, the employer had the crane start to remove the deck mats. Employee #1 was rigging slings from the crane to the steel plates when one plate became caught on the edge of the guardrail. The plate shifted and moved sideways, striking Employee #1. He sustained a fractured ankle, for which he was hospitalized.